package csdn.jihe.li14;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class Test {
    public static void main(String[] args) {
        //Collections 集合工具类
        //没有继承，没有实现，父类->object
        //Arrays
        List<Integer> list=new ArrayList<>();
        Collections.fill(list, null);
        System.out.println(list);
    }
}
